This invention relates to battery electrolytes and more particularly to solid polymeric electrolytes.
Solid electrolytes have been shown to be a practical substitute for aqueous electrolytes in electrochemical cells or batteries wherein the electrolytes have been Ag.sub.3 SI, one of the family MAg.sub.4 I.sub.5 (M=K, Rb, Cs), or one of the -aluminas, M.sub.2 O. 11Al.sub.2 O.sub.3 (M=Li, Na, K, NH.sub.4, Tl, Ag, etc). Polymers offer the potential of being used as solid electrolytes because of their ability to be formed into thin films and the ability of some polymers to dissolve salts and transport ions. Polymeric electrolytes offer the advantage of being readily prepared in thin films of large area both of which reduce cell resistance and allow large current drains at low current densities. Polyethylene oxide, PEO, has been shown to dissolve and interact strongly with alkali metal salts. Thus, PEO can be used for polymeric electroytes. A few other polymers containing high concentrations of polar groups and highly flexible chains have been reported to dissolve salts. These include poly(propylene oxide), ##STR1## poly(epichlorohydrin), ##STR2## and more recently poly(ethylene succinate), ##STR3##
It would be desirable to have other polymeric electrolytes, particularly ones using salts other than alkali metal salts.